Crank case ventilator



Nov. 10, 1931. E, s, MA KS 1,830,846

CRANK CASE VENTILATOR Filed Sept. 26, 1928 i9 it;

g5 Z NVENTOR.

ATTORNEY.

Patented Nov. 10, 1931' UNITED STATES PATENT OFFICE EDWARD S. MARKS, OFSYRACUSE, NEW YORK, ASSIGNOR, BY MESN'E ASSIGNMENTS,

TO FRANKLIN DEVELOPMENT CORPORATION, OF SYRACUSE, NEW YORK, A COR-roas'non or NEW YORK CRANK CASE VENTILATOR Application filed September26, 1928. Serial No. 308,517.

This invention has for its object, a particularly simple and efficientmeans for ventilating the crank case of an internal combustion. engine,which ventilating means is controlled by the temperature of the crankcase.

The invention is based upon the fact that When the crank case interiorand the oil in the engine base is cold, a considerable blast of air isnecessary to expel the vapors which blow by the piston rings of theengine before these vapors condense in the base and otherwise affect thecrank case oil and that after the engine and the oil has become heatedto a predetermined temperature, not as much ventilation is required andhence, in some cases the continuing of the blast of air into the crankcase combined with the heated oil, builds up a. pressure whereby the oilblows outof the breather pipe and causes high oil consumption.

g The invention comprises primarily the overcoming of these diiiicultiesby thermostatically controllingtheamount of air necessary when the crankcase or engine base is cold to expel the vapors and to cut down ordiscontinue the air blast when the engine or the oil heats up.

. The invention consistsin the novel features and in the combinationsand constructions case of an internal combustion engine through an inletin the crank case located remote from the outlet or breather, and athermostatically operated valve for controlling the flow of air throughthe inlet, the valve being usually normally open to permit a full flowof air through the inlet and operable as the temperature of the oil orcrank case rises to close the inlet more or less.

I havehere illustrated my invention as embodied in an air cooled engineof the Franklin type. i i g In the drawings, 1 designates the crank casehaving an air inlet at 2 at its front end and an. outlet or breatherpipe 3 at its rear end.

4 designates the cylinders having jackets 5 through which a coolingcurrent of air is passed.

6 is an air conduit extending over the heads of the cylinders andcommunicating with the jackets 5 and also communicating at its front endwith the upper end of a fan casing 7 having a fan rotor 8 therein, thisbeing mounted upon the front end of the crank shaft of the engine. a

VVhen the engine is running, the impeller or rotor S blows the air fromthe fan casing 7, conduit 6 and downwardly over the cylinders 4;through. the jackets 5.

Preferably, the .air for ventilating the crank case is taken from thecooling system and consists of a conduit 9 connecting the upper ordischarge end of the fan casing with .the inlet 2 of the crankcase.Preferably, an air cleaner is embodied in the conduit 9, this aircleaner comprising an enlarged. closed cylindrical. casing 10. connectedat its upper end to one section 11 of the con duit- 9 and at its otherend to the section 12 of the conduit, whichsection 12 leads into thecrank case.

The'air cleaner further includes a cylin-. drical screen or sleeve 13mounted in the casinglO and spaced apart from the cylindrical wallsthereof and from the top wall of the casing andbeing secured to thebottom of the casing in communication with the conduit section 12. Asleeve 14 of straining material, preferably flannel encloses the screen13 and covers the open top of the screen 13. The lower end of the screen13 is shown as fitted over a nipple 15 on the bottom of the casing 10and fixed thereto as by soldering and the lower end of the flannelscreen14 is deflected'outwardly or formed with an annular flange 16 and theparts are held in position as by screws 18 extending through the bottomof the casing 10 and said flange 16. Usually, an annular gasket 19overlies the flange and the heads of the screens bear against thegasket. Preferably, the bottom of the casing and the cylindrical portionthereof are detachably connected in any suit-- able manner as by bayonetjoints and also, the casing 10 or the cylindrical part thereof isdetachably secured to the section 11 of the conduit 9 by a clamp 20 sothat the cylindrical part of the casing 10 can be readily removed forgiving access to the interior thereof.

21 is a coupling mounted in the wall of the crank case, it being hereshown as having a nipple threading into the wall of the crank case andas also being threaded at 22 at its outer end for receiving a collar 23,which couples the section 12 of the conduit thereto. The inlet passage 2is formed in this coupling 21. The thermostatic Valve is carried by thecoupling 21 and projects into the crank case and comprises asemi-tubular member 2& open along one side and having a wall 25 at itsinner end which closes the semi-tubular member at its inner end, and athermostat in the form of a flat reed 26 extending lengthwise of thesemi-tubular member 2% along the open side thereof, the thermostat orreed 26 being fixed at 2'? at one end and having its other end tree soas to flex under changes of temperature and hence, close the open sideof the member 24 more or less.

The thermostatic member 26 isnormally separated from the open. side ofthe semitubular member 24, that is, it is separated when the engine iscold, so that a current of air will pass into the crank case when theengine is cold and carry any vapors therein out through the breatherpipe. As the engine heats up, the reed or member 26 under the influenceof the heat, closes the open side of the semi-tubular member 241 more orless and hence, cuts off the blast of air.

This thermostatically controlled valve for crank case ventilators isparticularly advantageous in that when the interior of the crank case orthe oil therein is cold, a'considerable blast of air passes through thecrank case to expel the vapors which blow by the piston rings before thevapors condense, and in that after the engine has become heated so thatthe vapors do not form to any great extent and hence, but littleventilation is required, the blast of air is cut down more or less orentirely cut off and hence, lubricating oil vapors or lubricating oil insuspension in the air does not blow out through the breather pipe.

VVh-at I claim is:

1. An internal combustion engine, the crank case of which is providedwith an air ing a current of air through the inlet, in combination witha thermostatically operated valve for controlling the passage of airthrough the inlet.

2. An internal combustion engine, the crank case of which is providedwith an air inlet an d an air outlet both located above the level of theoil therein and means for passing a current of air into the crank casethrough the inlet, in combination with a thermo-operated valvecontrolled by the temperature of the crank case for controlling the flowof air through the inlet.

3. An internal" combustion engine, the crank case of which is providedWith an air inlet and an air outlet both located above the level of theoil. therein and means for passing a current of air into thecrank casethrough the inlet, in combination with a normally open thermo-operatedvalve controlled by the temperature of the crank case for controllingthe flow otair into the crank case through said inlet.

4. An internal combustion engine having its crank case provided with anair inlet and an air outlet both located above the level of the oiltherein and means for passing a current of air through the inlet, incombina tion with a normally open thermostatically operated valvemounted in the wall of the crank case to be subject to the temperatureof the crank case for controlling the passing of air through the inlet.

5. In an internal combustion engine having its crank case provided withan air inlet and an air outlet both located above the level of the oiltherein, the combination of a normally open thermostatically closablevalve in the inlet and means for blowing air through the inlet includinga conduit and an air filter in the conduit.

6. In an internal. combustion engine having an air cooling system, a fanfor creating a cooling current of air around the engine; an air conduitassociated with. said cooling system and connected with the engine crankcase, at a point above the oil level therein, for passing a portion ofthe air current to the crank case; an air outlet from the crank case ata point above the oil level therein; and a thermostatically operatedvalve for controlling the flow of air through the crank case.

In testimony whereof, I have hereunto signed my name, at Syracuse, inthe county of Onondaga, and in the State of New York, this 14th day ofSeptember, 1928.

' EDWARD S. MARKS.

inlet and an air outlet both located above the level of the oil thereinand means for pass-

